Question

lewis dot diagram worksheet
draw the lewis dot diagram of the following covalent compounds.
f₂\tno\to₂
hcn\th₂s\tco
h₃o⁺\to₃\tncl₃
c₂h₂\tch₂cl₂\tc₂h₄
ch₂o\tc₂h₆\tso₄²⁻

Explanation:

Step1: Calculate total valence electrons for NO

N (5) + O (6) = 11 valence electrons

Step2: Draw NO Lewis structure

$$:\dot{N}=\ddot{O}:$$
(Note: One unpaired electron on N, satisfies octet for O, 7 electrons on N)

Step3: Calculate total valence electrons for HCN

H (1) + C (4) + N (5) = 10 valence electrons

Step4: Draw HCN Lewis structure

$$H-C\equiv N:$$

Step5: Calculate total valence electrons for H₂S

2×H (1) + S (6) = 8 valence electrons

Step6: Draw H₂S Lewis structure

$$\begin{matrix} & :\ddot{S}: & \\ H & & H \end{matrix}$$

Step7: Calculate total valence electrons for CO

C (4) + O (6) = 10 valence electrons

Step8: Draw CO Lewis structure

$$:C\equiv O:$$

Step9: Calculate total valence electrons for H₃O⁺

3×H (1) + O (6) - 1 (charge) = 8 valence electrons

Step10: Draw H₃O⁺ Lewis structure

$$\begin{matrix} & H & \\ & | & \\ H-\ddot{O}-H & & \\ & ^+ & \end{matrix}$$

Step11: Calculate total valence electrons for O₃

3×O (6) = 18 valence electrons

Step12: Draw O₃ Lewis structure (resonance form)

$$:\ddot{O}-\ddot{O}=\ddot{O}: \longleftrightarrow :\ddot{O}=\ddot{O}-\ddot{O}:$$

Step13: Calculate total valence electrons for NCl₃

N (5) + 3×Cl (7) = 26 valence electrons

Step14: Draw NCl₃ Lewis structure

$$\begin{matrix} & :\ddot{Cl}: & \\ & | & \\ :\ddot{Cl}-\ddot{N}-\ddot{Cl}: & & \\ & : & : \end{matrix}$$

Step15: Calculate total valence electrons for C₂H₂

2×C (4) + 2×H (1) = 10 valence electrons

Step16: Draw C₂H₂ Lewis structure

$$H-C\equiv C-H$$

Step17: Calculate total valence electrons for CH₂Cl₂

C (4) + 2×H (1) + 2×Cl (7) = 20 valence electrons

Step18: Draw CH₂Cl₂ Lewis structure

$$\begin{matrix} & :\ddot{Cl}: & \\ & | & \\ H-\ddot{C}-H & & \\ & | & \\ & :\ddot{Cl}: & \end{matrix}$$

Step19: Calculate total valence electrons for C₂H₄

2×C (4) + 4×H (1) = 12 valence electrons

Step20: Draw C₂H₄ Lewis structure

$$\begin{matrix} H & & H \\ | & & | \\ H-C=C-H & & \end{matrix}$$

(Each C has two lone pairs implied in octet, shown as:

$$\begin{matrix} H & & H \\ | & & | \\ H-\ddot{C}=\ddot{C}-H & & \end{matrix}$$

)

Step21: Calculate total valence electrons for CH₂O

C (4) + 2×H (1) + O (6) = 12 valence electrons

Step22: Draw CH₂O Lewis structure

$$\begin{matrix} & H & \\ & | & \\ H-\ddot{C}=\ddot{O} & & \end{matrix}$$

Step23: Calculate total valence electrons for C₂H₆

2×C (4) + 6×H (1) = 14 valence electrons

Step24: Draw C₂H₆ Lewis structure

$$\begin{matrix} H & H & \\ | & | & \\ H-\ddot{C}-\ddot{C}-H & & \\ | & | & \\ H & H & \end{matrix}$$

Step25: Calculate total valence electrons for SO₄²⁻

S (6) + 4×O (6) + 2 (charge) = 32 valence electrons

Step26: Draw SO₄²⁻ Lewis structure (resonance form)

$$\begin{matrix} & :\ddot{O}: & \\ & || & \\ :\ddot{O}-\ddot{S}-\ddot{O}: & & \\ & | & \\ & :\ddot{O}: & \\ & ^{2-} & \end{matrix}$$

(One double bond, three single bonds; resonance swaps double bond position)

Answer:

1. $F_2$ (completed): $:\ddot{F}-\ddot{F}:$
2. $NO$: $:\dot{N}=\ddot{O}:$
3. $O_2$ (completed, corrected): $:\ddot{O}=\ddot{O}:$
4. $HCN$: $H-C\equiv N:$
5. $H_2S$:

$$\begin{matrix} & :\ddot{S}: & \\ H & & H \end{matrix}$$

1. $CO$: $:C\equiv O:$
2. $H_3O^+$:

$$\begin{matrix} & H & \\ & | & \\ H-\ddot{O}-H & & \\ & ^+ & \end{matrix}$$

1. $O_3$: $:\ddot{O}-\ddot{O}=\ddot{O}: \longleftrightarrow :\ddot{O}=\ddot{O}-\ddot{O}:$
2. $NCl_3$:

$$\begin{matrix} & :\ddot{Cl}: & \\ & | & \\ :\ddot{Cl}-\ddot{N}-\ddot{Cl}: & & \\ & : & : \end{matrix}$$

1. $C_2H_2$: $H-C\equiv C-H$
2. $CH_2Cl_2$:

$$\begin{matrix} & :\ddot{Cl}: & \\ & | & \\ H-\ddot{C}-H & & \\ & | & \\ & :\ddot{Cl}: & \end{matrix}$$

1. $C_2H_4$:

$$\begin{matrix} H & & H \\ | & & | \\ H-\ddot{C}=\ddot{C}-H & & \end{matrix}$$

1. $CH_2O$:

$$\begin{matrix} & H & \\ & | & \\ H-\ddot{C}=\ddot{O} & & \end{matrix}$$

1. $C_2H_6$:

$$\begin{matrix} H & H & \\ | & | & \\ H-\ddot{C}-\ddot{C}-H & & \\ | & | & \\ H & H & \end{matrix}$$

1. $SO_4^{2-}$:

$$\begin{matrix} & :\ddot{O}: & \\ & || & \\ :\ddot{O}-\ddot{S}-\ddot{O}: & & \\ & | & \\ & :\ddot{O}: & \\ & ^{2-} & \end{matrix}$$

(resonance structures exist)